Rename Slave to Host

The role of a slave as a host for Factorio servers is not well reflected
in its name and has caused confusion among users.  Rename slave to host
to better reflect its role as a host of Factorio servers.

test/host.js

@@ -0,0 +1,112 @@
+"use strict";
+const assert = require("assert").strict;
+const path = require("path");
+
+const libConfig = require("@clusterio/lib/config");
+const Host = require("@clusterio/host/src/Host");
+
+describe("Host testing", function() {
+	before(function() {
+		libConfig.InstanceConfig.finalize();
+	});
+
+	describe("discoverInstances()", function() {
+		it("should discover test instance", async function() {
+			let instancePath = path.join("test", "file", "instances");
+			let instanceInfos = await Host._discoverInstances(instancePath);
+
+			let referenceConfig = new libConfig.InstanceConfig("host");
+			await referenceConfig.init();
+			referenceConfig.set("instance.id", 1);
+			referenceConfig.set("instance.name", "test");
+
+			assert.deepEqual(instanceInfos, new Map([
+				[1, {
+					config: referenceConfig,
+					path: path.join(instancePath, "test"),
+				}],
+			]));
+		});
+	});
+
+	describe("class Host", function() {
+		describe(".syncUserListsEventHandler()", function() {
+			let mockHost;
+			beforeEach(function() {
+				mockHost = {
+					adminlist: new Set(),
+					whitelist: new Set(),
+					banlist: new Map(),
+					broadcasts: [],
+					broadcastEventToInstance(message, event) {
+						this.broadcasts.push(message["data"]);
+					},
+					syncUserListsEventHandler: Host.prototype.syncUserListsEventHandler,
+					syncLists(adminlist, banlist, whitelist) {
+						return this.syncUserListsEventHandler({ "data": {
+							"adminlist": adminlist,
+							"banlist": banlist,
+							"whitelist": whitelist,
+						}});
+					},
+				};
+			});
+
+			it("should broadcast new entries to adminlist", async function() {
+				await mockHost.syncLists(["admin1"], [], []);
+				await mockHost.syncLists(["admin1", "admin2"], [], []);
+
+				assert.deepEqual(mockHost.broadcasts, [
+					{ "name": "admin1", "admin": true },
+					{ "name": "admin2", "admin": true },
+				]);
+			});
+
+			it("should broadcast removals from adminlist", async function() {
+				mockHost.adminlist.add("admin1").add("admin2");
+				await mockHost.syncLists(["admin1"], [], []);
+				assert.deepEqual(mockHost.broadcasts, [
+					{ "name": "admin2", "admin": false },
+				]);
+			});
+
+			it("should broadcast new entries to whitelist", async function() {
+				await mockHost.syncLists([], [], ["player1"]);
+				await mockHost.syncLists([], [], ["player1", "player2"]);
+
+				assert.deepEqual(mockHost.broadcasts, [
+					{ "name": "player1", "whitelisted": true },
+					{ "name": "player2", "whitelisted": true },
+				]);
+			});
+
+			it("should broadcast removals from whitelist", async function() {
+				mockHost.whitelist.add("player1").add("player2");
+				await mockHost.syncLists([], [], ["player1"]);
+
+				assert.deepEqual(mockHost.broadcasts, [
+					{ "name": "player2", "whitelisted": false },
+				]);
+			});
+
+			it("should broadcast new entries to banlist", async function() {
+				await mockHost.syncLists([], [["badie1", "greifing"]], []);
+				await mockHost.syncLists([], [["badie1", "greifing"], ["badie2", "annoying"]], []);
+
+				assert.deepEqual(mockHost.broadcasts, [
+					{ "name": "badie1", "banned": true, "reason": "greifing" },
+					{ "name": "badie2", "banned": true, "reason": "annoying" },
+				]);
+			});
+
+			it("should broadcast removals to banlist", async function() {
+				mockHost.banlist.set("badie1", "greifing").set("badie2", "annoying");
+				await mockHost.syncLists([], [["badie1", "greifing"]], []);
+
+				assert.deepEqual(mockHost.broadcasts, [
+					{ "name": "badie2", "banned": false, "reason": "" },
+				]);
+			});
+		});
+	});
+});